S.M.A.R.T. Value "C5" ... and pending drive failure warning

My QNAP NAS warned of a SMART error on one of its Red 4TB drives (WD40EFRX). A bad-block scan on the NAS would not clear the error, so I pulled the drive. {Footnote}

Testing the Red drive on a Win 10 PC using WD DLG … quick test and extensive test … indicate that the drive is serviceable. Serviceable. In spite of the SMART “C5” flag, “Current Pending Sector Count” with a raw value of 1.

CrystalDrive reports this error similarly to the QNAP NAS, with a health status of “Caution”.

The drive is essentially useless for the NAS in its current state. My question to y’all readers, are there any guesses at whether there is a good correlation between this drive’s SMART C5 state and the occurrence of a future unrecoverable error?

{Footnote} I got to watch how the “enclosure spare” automatically was joined into the affected RAID5 Group … as well as the automatic rebuild kick off. The rebuild completed, and my NAS is back to being serviceable.

{Footnote 2} I HATE automatic formatting. Assuming an asterisk always is meant by the author as a bullet is idiotic on the part of the dill-wad who spec’ed out this functionality.

I would recommend replacing the hard drive under warranty. A free replacement can be requested in the following link:

Thanks, Trancer, for the advice!

The RMA is scheduled already, but I wonder whether the drive I receive will be in worse shape, than the one that I send in. It seems that RMA-replacement drives leave WDC in a somewhat indeterminate state.

I’ve since cleared this drive’s “C5” SMART error by writing ‘all ones’ to the drive using WDC Data Lifeguard Diagnostics while I was waiting for the RMA information.



Search as I might (perhaps my Google-Fu is too weak :anguished:), I can’t determine if there is a correlation between the first detected C5 error – which is subsequently cleared – and a subsequent drive failure. All the more so, that now there is now evidence of the previous error.

I’d appreciate pointer(s) from any and all! Thanks!